Wild_Bill wrote:
Very good idea, Winston.. it hadn't occurred to me to integrate
something into the battery cover, and your solution is ingenious in
terms of simplifying the modification.

Thanks, Bill.

I guess that's why I hadn't added a switch to the cable plug cover (on
the top side), which would require removing material from the cover,
opening the display housing and various other steps.. the big one being
that the calipers still work reliably after being reassembled.

If you captured the battery cover to your CAD program, you could create
a version of it that included a brass insert for a 3 mm screw.
Scrap a keyboard for the carbon button and you are almost done:
http://www.pcguide.com/ref/kb/const/switchRubber-c.html

Keep us posted, please.

--Winston